THE OPERATION, LIFE AND RELIABILITY OF DISCHARGE LAMPS

A review is presented of the main light sources which are of particular interest, and information is included on both design and operation. The light sources described are the modern high pressure mercury vapour lamp (mbf) which consists essentially of a high purity fused quartz arc tube, charged with mercury and a low pressure of argon; low pressure sodium lamps (sox and sli) in both linear and 'U' tube versions consisting of a glass arc tube containing coiled tungsten electrodes at each end impregnated with an electron emissive material; and the newest in the range, the high pressure sodium lamp (son). This is a much more compact and robust lamp, consisting of an arc tube fabricated from a translucent polycrystalline alumina ceramic resistant to attack by hot sodium vapour; it has a melting point of 2050 deg C. The principal failure modes of these light sources, respectively, are described by reference to electrode/emissive coating degradation and loss; loss of emission from the cathode or clean-up of argon both of which prevent the lamp from starting and mechanical failures induced by vibration; and loss of sodium caused by a very slow reaction with the alumina ceramic, over many thousands of hours, causing voltage rise and, eventually, instability. External factors influencing the life of such gas discharge lamps such as wind buffeting, vibration and extreme environmental conditions are discussed. Reference is made also to failure problems associated with low supply voltage, control gear, starting devices, etc. /TRRL/

  • Corporate Authors:

    Association of Public Lighting Engineers

    78 Buckingham Gate, Westminster
    London SW1E 6PF,   England 
  • Authors:
    • Coaton, J R
  • Publication Date: 1978

Media Info

  • Features: References; Tables;
  • Pagination: p. 112-114
  • Serial:
    • Public Lighting
    • Volume: 43
    • Issue Number: 183
    • Publisher: Association of Public Lighting Engineers

Subject/Index Terms

Filing Info

  • Accession Number: 00194430
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jul 11 1979 12:00AM